In recent years, as positioning functions become popular in mobile information terminals, a so-called positional service to provide a service in accordance with a position of a mobile information terminal to a user is provided. For example, in order to avoid forgetting to get off the train, there is so-called location alarm to notify a user of getting close to a destination station. Such location alarm is used not only to avoid forgetting to get off the train but also to notify a user of getting close to a destination location (such as a dry cleaner's and a supermarket), for example, intended to stop by on the way home from work.
While the convenience of users is improved by such positional service, the increase in power consumption becomes a problem in location alarm because the positioning function of a mobile information terminal has to be operated continuously.
Therefore, various techniques to reduce power consumption are developed. For example, there is a disclosed technique to lower the power consumption by increasing the frequency of position calculation when the distance to a destination location is close and by decreasing the frequency of position calculation when the distance to a destination location is far.
An example of the related art is disclosed in Japanese Patent No.